1. Field
The present disclosure is directed to a method and apparatus for neighbor assisted combining for localized multicast services. More particularly, the present disclosure is directed to establishing at least one serving cell and at least one extended serving cell for broadcast and multicast services.
2. Description of Related Art
Presently, to deliver a multicast/broadcast stream in the Radio Access network (RAN) efficiently, two possible methods can be used. One is simulcast and the other is localized multicast. In simulcast mode, a Multimedia Broadcast Multicast Service (MBMS) service area is identical to the RAN system coverage area. All the cells broadcast the same data using the same resource. In Orthogonal Frequency Division Multiplexing (OFDM) based Enhanced MBMS (EMBMS), this could minimize the inter-cell interference if the allocated resource element (RE) is identical, which can maximize the Bits/Hz. For a service with very large number of users and the service is widely distributed in the RAN, simulcast can be an efficient way to go. For example, simulcast can be useful for transmission of weather reports, music, movies, etc.
Simulcast is not efficient if the service area is much smaller than the system coverage area. For example, if the service is mostly focused in selected multiple cells, such as for clip replay for football stadiums, sport centers, local weather reports, or the like, it is not good to turn on all the cells in the system to deliver the localized service to just the selected cells. Most of the MBMS service may fall into this category of localized MBMS. In other words, simulcast is not an efficient way to maximize the Bits/Hz/km2. For the localized MBMS service, counting can be applied to determine the user status of the cells, such as to determine which cells contain users who desire the service. Then an efficient radio bearer will be established in the appropriate cells to deliver the stream.
Unfortunately, during a localized multicast session, neighboring cells interfere with the localized service area cells. For example, neighbor cells may transmit on the same resource element as the serving cells, which will interfere with the common multicast transmission. Thus, there is a need for a method and apparatus for neighbor assisted combining for localized multicast services.